Standardised monitoring of marine species and their populations is important for fisheries management. However, implementing monitoring programmes require extensive resources. In Denmark, a portion of the income obtained from the angling and recreational fishing license is supporting several scientific projects in fresh and coastal marine environment, including stocking, restoration and monitoring. This is known as Fiskepleje. The Key Fisher Project (Nøglefiskerprojektet) is a citizen science programme that has been monitoring the Danish coastal zone for 20 years, supported by Fiskepleje, where no other official monitoring is in place. Each month, recreational fishers deploy standardised gear on fixed positions along the Danish coasts and inside the fjords where they register the fish catches, as a proxy for fish assemblages in the area. The Key Fisher Project is a successful example of how a long-term citizen science programme can contribute to the monitoring of coastal fish stocks in an efficient and cost- effective manner, providing important time-series data on coastal fish assemblages
